Activation of human peripheral blood T cells does not lead to increased P-glycoprotein expression

Xi Y. Mu, Michael P. Gosland, Mary M. Bartik, Julia Schimmelpfennig, Neil Elliot Kay

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

The expression of P-glycoprotein (Pgp) on normal human lymphocytes, and its drug exclusion capacity, implies that Pgp might be involved in cytokine secretion. We used two-color flow cytometry to detect simultaneously Pgp expression and IL-2 accumulation in resting and mitogen-activated human lymphocytes. Among resting lymphocytes from five healthy donors less than 1% were Pgp + as determined by reactivity with the anti-Pgp monoclonal antibody (mAb) 4E3. The percentage of Pgp + lymphocytes increased to 3% after 24 hr of mitogenic stimulation that induced maximal production of cytoplasmic IL-2. The percentage of lymphocytes that coexpressed membrane Pgp and cytoplasmic IL-2 accounted for <10% of the total IL-2 producing lymphocytes. Finally, mitogen-induced cytoplasmic IL-2 accumulation was enhanced by stimulation in the presence of monensin but not the Pgp functional inhibitor verapamil. Because mAb 4E3 detected lower than expected numbers of Pgp + lymphocytes, we compared the binding of mAbs MRK16 and 4E3 concomitant with doxorubicin (DOX)-uptake by K562 and R7 tumor cells and purified CD8 + lymphocytes. The MRK16 mAb was found to be sensitive but not very specific (30%). In contrast, the sensitivity of 4E3 was equivalent to MRK16 (98%) and was highly specific (98.5%). There was also a positive association between DOX efflux and the level of Pgp expression as detected by 4E3 but not MRK16. Thus, human T cells do not markedly up-regulate their expression of functional Pgp molecules as detected by mAb 4E3 following activation, suggesting that Pgp does not play a major role in IL-2 secretion by activated T cells.

Original languageEnglish (US)
Pages (from-to)239-246
Number of pages8
JournalJournal of Clinical Immunology
Volume19
Issue number4
DOIs
StatePublished - 1999
Externally publishedYes

Fingerprint

P-Glycoprotein
Blood Cells
T-Lymphocytes
Lymphocytes
Interleukin-2
Monoclonal Antibodies
Mitogens
Doxorubicin
Monensin
Verapamil
Flow Cytometry
Up-Regulation
Color
Cytokines

Keywords

  • Cytokine secretion
  • Multidrug resistance

ASJC Scopus subject areas

  • Immunology and Allergy
  • Immunology

Cite this

Activation of human peripheral blood T cells does not lead to increased P-glycoprotein expression. / Mu, Xi Y.; Gosland, Michael P.; Bartik, Mary M.; Schimmelpfennig, Julia; Kay, Neil Elliot.

In: Journal of Clinical Immunology, Vol. 19, No. 4, 1999, p. 239-246.

Research output: Contribution to journalArticle

Mu, Xi Y. ; Gosland, Michael P. ; Bartik, Mary M. ; Schimmelpfennig, Julia ; Kay, Neil Elliot. / Activation of human peripheral blood T cells does not lead to increased P-glycoprotein expression. In: Journal of Clinical Immunology. 1999 ; Vol. 19, No. 4. pp. 239-246.
@article{83067f0ef90342789a1f3440b2baf5df,
title = "Activation of human peripheral blood T cells does not lead to increased P-glycoprotein expression",
abstract = "The expression of P-glycoprotein (Pgp) on normal human lymphocytes, and its drug exclusion capacity, implies that Pgp might be involved in cytokine secretion. We used two-color flow cytometry to detect simultaneously Pgp expression and IL-2 accumulation in resting and mitogen-activated human lymphocytes. Among resting lymphocytes from five healthy donors less than 1{\%} were Pgp + as determined by reactivity with the anti-Pgp monoclonal antibody (mAb) 4E3. The percentage of Pgp + lymphocytes increased to 3{\%} after 24 hr of mitogenic stimulation that induced maximal production of cytoplasmic IL-2. The percentage of lymphocytes that coexpressed membrane Pgp and cytoplasmic IL-2 accounted for <10{\%} of the total IL-2 producing lymphocytes. Finally, mitogen-induced cytoplasmic IL-2 accumulation was enhanced by stimulation in the presence of monensin but not the Pgp functional inhibitor verapamil. Because mAb 4E3 detected lower than expected numbers of Pgp + lymphocytes, we compared the binding of mAbs MRK16 and 4E3 concomitant with doxorubicin (DOX)-uptake by K562 and R7 tumor cells and purified CD8 + lymphocytes. The MRK16 mAb was found to be sensitive but not very specific (30{\%}). In contrast, the sensitivity of 4E3 was equivalent to MRK16 (98{\%}) and was highly specific (98.5{\%}). There was also a positive association between DOX efflux and the level of Pgp expression as detected by 4E3 but not MRK16. Thus, human T cells do not markedly up-regulate their expression of functional Pgp molecules as detected by mAb 4E3 following activation, suggesting that Pgp does not play a major role in IL-2 secretion by activated T cells.",
keywords = "Cytokine secretion, Multidrug resistance",
author = "Mu, {Xi Y.} and Gosland, {Michael P.} and Bartik, {Mary M.} and Julia Schimmelpfennig and Kay, {Neil Elliot}",
year = "1999",
doi = "10.1023/A:1020572114862",
language = "English (US)",
volume = "19",
pages = "239--246",
journal = "Journal of Clinical Immunology",
issn = "0271-9142",
publisher = "Springer New York",
number = "4",

}

TY - JOUR

T1 - Activation of human peripheral blood T cells does not lead to increased P-glycoprotein expression

AU - Mu, Xi Y.

AU - Gosland, Michael P.

AU - Bartik, Mary M.

AU - Schimmelpfennig, Julia

AU - Kay, Neil Elliot

PY - 1999

Y1 - 1999

N2 - The expression of P-glycoprotein (Pgp) on normal human lymphocytes, and its drug exclusion capacity, implies that Pgp might be involved in cytokine secretion. We used two-color flow cytometry to detect simultaneously Pgp expression and IL-2 accumulation in resting and mitogen-activated human lymphocytes. Among resting lymphocytes from five healthy donors less than 1% were Pgp + as determined by reactivity with the anti-Pgp monoclonal antibody (mAb) 4E3. The percentage of Pgp + lymphocytes increased to 3% after 24 hr of mitogenic stimulation that induced maximal production of cytoplasmic IL-2. The percentage of lymphocytes that coexpressed membrane Pgp and cytoplasmic IL-2 accounted for <10% of the total IL-2 producing lymphocytes. Finally, mitogen-induced cytoplasmic IL-2 accumulation was enhanced by stimulation in the presence of monensin but not the Pgp functional inhibitor verapamil. Because mAb 4E3 detected lower than expected numbers of Pgp + lymphocytes, we compared the binding of mAbs MRK16 and 4E3 concomitant with doxorubicin (DOX)-uptake by K562 and R7 tumor cells and purified CD8 + lymphocytes. The MRK16 mAb was found to be sensitive but not very specific (30%). In contrast, the sensitivity of 4E3 was equivalent to MRK16 (98%) and was highly specific (98.5%). There was also a positive association between DOX efflux and the level of Pgp expression as detected by 4E3 but not MRK16. Thus, human T cells do not markedly up-regulate their expression of functional Pgp molecules as detected by mAb 4E3 following activation, suggesting that Pgp does not play a major role in IL-2 secretion by activated T cells.

AB - The expression of P-glycoprotein (Pgp) on normal human lymphocytes, and its drug exclusion capacity, implies that Pgp might be involved in cytokine secretion. We used two-color flow cytometry to detect simultaneously Pgp expression and IL-2 accumulation in resting and mitogen-activated human lymphocytes. Among resting lymphocytes from five healthy donors less than 1% were Pgp + as determined by reactivity with the anti-Pgp monoclonal antibody (mAb) 4E3. The percentage of Pgp + lymphocytes increased to 3% after 24 hr of mitogenic stimulation that induced maximal production of cytoplasmic IL-2. The percentage of lymphocytes that coexpressed membrane Pgp and cytoplasmic IL-2 accounted for <10% of the total IL-2 producing lymphocytes. Finally, mitogen-induced cytoplasmic IL-2 accumulation was enhanced by stimulation in the presence of monensin but not the Pgp functional inhibitor verapamil. Because mAb 4E3 detected lower than expected numbers of Pgp + lymphocytes, we compared the binding of mAbs MRK16 and 4E3 concomitant with doxorubicin (DOX)-uptake by K562 and R7 tumor cells and purified CD8 + lymphocytes. The MRK16 mAb was found to be sensitive but not very specific (30%). In contrast, the sensitivity of 4E3 was equivalent to MRK16 (98%) and was highly specific (98.5%). There was also a positive association between DOX efflux and the level of Pgp expression as detected by 4E3 but not MRK16. Thus, human T cells do not markedly up-regulate their expression of functional Pgp molecules as detected by mAb 4E3 following activation, suggesting that Pgp does not play a major role in IL-2 secretion by activated T cells.

KW - Cytokine secretion

KW - Multidrug resistance

UR - http://www.scopus.com/inward/record.url?scp=0032845403&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0032845403&partnerID=8YFLogxK

U2 - 10.1023/A:1020572114862

DO - 10.1023/A:1020572114862

M3 - Article

C2 - 10471978

AN - SCOPUS:0032845403

VL - 19

SP - 239

EP - 246

JO - Journal of Clinical Immunology

JF - Journal of Clinical Immunology

SN - 0271-9142

IS - 4

ER -